Lighting
- This article is about illumination of the dungeon (or lack thereof). For light in other contexts, see Light (disambiguation).
- For darkness in other contexts, see dark.
Lighting, or simply light, is an element of the dungeon in NetHack. Lighting determines how illuminated a given room or portion of the level is, specifically whether it is lit or unlit—in turn, this affects the visibility of items, dungeon features, monsters, and other elements such as revealed traps within that area.
If the hero is blind, they cannot see anything at all regardless of the area's lighting unless they have the aid of other items or certain properties.
A user has suggested improving this page or section as follows:
"Consider images. Hold off on updating the version template until the article is updated enough."
Lighting per square
Each square on a dungeon level will either be lit or be unlit at level generation. Corridors are always generated as unlit by default, while a room can be generated as entirely lit or unlit, with the frequency of dark rooms increasing as the hero enters deeper dungeon levels.
Lit areas can be displayed in brighter characters using the lit_corridor game option, while unseen areas of lit rooms can be drawn as if they were unlit using the dark_room option.
Lighting per level
Some levels consist of a singular "room", open area or closed area that can be completely dark, partially lit or completely lit. Branches such as the Gnomish Mines and Gehennom will often feature fully-dark levels: a filler level on the Gnomish Mines
The Big Room is a special type of level consisting of a singular massive room whose lighting can vary based on the map used to generate it: map #2 has three different lighting patterns, while map #9 has a lit area surrounding lava, with the rest of the level being unlit.
Vision and light
A hero is always capable of seeing the squares adjacent to them, including anything visible such as objects or monsters that occupy those squares. A hero that is not blind can also see any object or monster that currently occupies a lit square, as long as there is no wall, cloud (including poison clouds) or closed door obstructing the hero's line of sight—an object or monster that occupies an unlit square cannot be seen normally by the hero, although dark squares do not inhibit seeing into other lit areas.
Infravision makes certain monsters in the hero's line of sight visible to them, regardless of if that monster's current square is lit or unlit. A hero that is trapped in a pit or spiked pit cannot see beyond the edges of the pit, restricting their vision to adjacent squares only regardless of the area's lighting.
Object locations 'remembered' by the hero are not counted in both of the above cases, as the object may have been moved from that location between the last time the hero saw it there and the next time they see that square: a remembered object location is cleared if the hero visits it and sees that the object is no longer there, or else if the hero employs a source of object detection (which clears and then properly maps object locations at the time of its use).[1][2][3][4]
Some squares and locations cannot be lit, such as the ares under moats or pools of water. Other areas such as the inside of a monster engulfing the hero can be "lit", but have little to no benefit from doing so.
Lighting and darkening areas
It is possible to permanently light a hero's surroundings through the following methods:
- Reading a non-cursed scroll of light
- Casting the light spell
- Zapping a wand of light
Squares lit this way will remain so unless darkness is spread that covers those squares.
Similarly, it is possible to spread darkness in an already-lit area: reading a cursed scroll of light, or reading a scroll of light of any beatitude while confused, will darken the hero's surroundings. Squares darkened this way will remain so unless light is spread that covers those squares.
Light sources
A light source is a tool or other object, such as a lamp or candle, that temporarily or otherwise lights a given area around it.
Gremlins and light
The gremlin is a monster that possesses a unique vulnerability to various forms of light:
- Zapping a wand of light, reading a non-cursed scroll of light, or casting the light spell will deal d5 damage to gremlins in the light radius.[5][6]
- Applying a wand of light to break it will deal (1 + charges)d4 damage to gremlins caught in the blast, with a cap of 20.[7]
- Applying an expensive camera will do d4 damage to gremlins caught in the flash.[8]
- Sunsword does +d8 damage against gremlins that it hits, and the light the artifact emits while wielded will scare them if they are within its radius.[9]
A hero that polymorphs into a gremlin inherits this weakness.[10]
References
- ↑ src/detect.c in NetHack 3.6.7, line 284: clear_stale_map()
- ↑ src/detect.c in NetHack 3.6.7, line 312: call from gold_detect()
- ↑ src/detect.c in NetHack 3.6.7, line 465: call from food_detect()
- ↑ src/detect.c in NetHack 3.6.7, line 666: call from object_detect() if there were no stale markings to clear
- ↑ src/zap.c in NetHack 3.6.7, line 2161
- ↑ src/read.c in NetHack 3.6.7, line 2018
- ↑ src/zap.c in NetHack 3.6.7, line 2623
- ↑ src/uhitm.c in NetHack 3.6.7, line 3145: Gremlins take damage from light
- ↑ src/weapon.c in NetHack 3.6.7, line 328
- ↑ src/zap.c in NetHack 3.6.7, line 2614
This page may need to be updated for the current version of NetHack.
It may contain text specific to NetHack 3.4.3. Information on this page may be out of date.
Editors: After reviewing this page and making necessary edits, please change the {{nethack-343}} tag to the current version's tag or {{noversion}} as appropriate.
